In recent years, developments of GaN-based LED have drawn extensive attention across the world. It has such inspiring advantages as over 50,000 hours service life, over 100 lm/W light effect and environmental protection. Many governments are vigorously promoting applications of the LEDs and propose to successively cancel usage of the incandescent lamps. However, to replace the incandescent lamps, the LEDs are restricted to such applications as general lighting and outdoor lighting due to poor luminance performance.
To improve luminous efficiency is an important approach to increase luminance Deficiencies such as electrode light blocking and current blocking of standard chips have restricted luminous efficiency improvement. Therefore, vertical-structure and flip-chip structures are widely applied. The flip-chip structure has the electrode on the bottom and therefore avoids the metal electrode's blocking and absorption as the light is emitted upways. However, in prior art, fabricating the n electrode of flip-chip structure requires to etching part of the p-type layer and the active layer, and to exposing the n-type layer. Then, fabricate the n-type electrode on the n-type layer. Etching part of the p-type layer and the active layer loses the active layer area and influences luminous efficiency improvement. In addition, it restricts effective application of light emitted from the LED chip side wall.